Effect of extrusion ratio on mechanical and corrosion properties of AZ31B alloys prepared by a solid recycling process

Some AZ31B magnesium alloy bars were prepared by a solid recycling process with different extrusion ratios. A reference specimen was processed by extruding an as-received AZ31 ingot. The microstructures, mechanical and corrosion properties of AZ31B magnesium recycled specimens were investigated. With increasing extrusion ratio, the yield strength, tensile strength and yield ratio increases. The reliability of the recycled alloy is poorer than the reference specimen. The corrosion rates of recycled AZ31B magnesium specimens increase immersed in both alkaline and neutral 4% NaCl solution with a decrease extrusion ratio. The corrosion resistance of recycled AZ31B magnesium specimens is improved with increasing pH of immersed solution. The recycled specimens show superior corrosion resistance than reference specimen.

Research highlights
► We recycled AZ31B by solid-state processing with different extrusion ratio.
► The reliability of recycled AZ31B is poorer than that of extruded from ingot.
► Increasing the extrusion ratio leads to improved reliability.
► Corrosion resistance of recycled AZ31B increases with increasing extrusion ratio.